Oil-guard.



B. H. HAMILTON.

OIL GUARD.

ABPLIOATION FILED Nov. 1, 1906.

BR'AQE H. HAMILTON, 0F LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION' 0F NEXV YORK.

0113- GUARD.

Specification of Letters Patent.

Patented Mar. 5, 1912.

Application filedV November 1, 1906. Serial No. 341,586.

'To all whom it may concern:

Be it known that l, BnAcn H. HAMinroN, a citizen of the Unite(` States, residing at Lynn, county of Essex, State of Massachusetts, have invented certain new and useful Improvements in .Oil-Guards, ot which the following is a specification.

In the construction of dynamo electric machines it is desirable to locate one or both bearingsclose to the revolvingrmember to reduce the longitudinal dimension .of the machine. To cool the machine, said member is provided with one or more air passages or 'ducts through which an active circulation of air is maintained, the air enter-p` ing at one or more points near the shaft and discharging at the periphery. Owing to'the close proximity of the parts the rotation of the armature sucks' oil mixed with air from the bearing and discharges it into and' through the ducts in said rotating member and into the stationary member Surrounding it. A.

My invention has for its object to 'over-V come the objection referred to without, howv ever, increasing the longitudinal dimension ot the machine. l

vIn the accompanying drawing which y illustrates one of the embodiments ot my inv'ention, Figure l is a partial view of a dynamo electric machine with certain of the parts in section, and Fig.` 2 a sectional view taken on line 2 2 of Fig. i.

1 represents the casing ot a dynamo electric machine provided with2 suitable pole pieces and windings therefor.

The invention is applicable to 'alternating or direct current machines and the specific construction of the field magnet and the armature are immaterial.

2 in this instance represents the revolvin member of the machine and il the sha t therefor. The revolving element is made of laminated magnetic .material 4 with heavy end heads 5 that serve to clamp the laminac and hold the same in a fixed position on the shaft. Extending axially through the lam-l intr and the heads are one or more passages 6 through which air t'or cooling is drawn and discharged through the radial passages 7, the latter heilig formed by suitable space blocks located between adjacent bundles ot laminar: and between the laminae and the end heads. The periphery ot the revolving member is provided with windings 8 `ot any tratedgit Iwill depend `chiefly upon whether or not 1t willlbe in the same position with respect to the armature as the one shown.

-On the sha-ft is a collar l1 forming a part ot' 'an oil thrower to prevent the oil 'trom working out of the bearing intothe revolving element of the dynamo. As a further precaution `the collar is provided with a cylindrical portion 12 that makes a close fit with the surrounding portion of the bearing.

.ingl the same or diiierent from the one illus- I have found .that in spite of the oil thrower f and the close lit between thebearing' and the cylindrical portion 12, that oil will bc sucked i out from the bearing and discharged into and through the passages G and 7. Y Thisis caused by the fact that the air pressure just outside` of the bearing and immediately surrounding the shaft, is lower than that withinthe hearingdue tothe rapid rotation of the revolving member which acts like a centrifugal fan and causes air to be drawn away from the inner end ot' the hearing. ln order to prevent this l have discovered that it is necessary to maintain around the outside of `the bearing and adjacent the revoking member, a region wherein the pressureI is the same or substantially the same as that ot' the air within the bearing. ln any cvcnt it must nothe appreciably lcss, but it. can be somewhat higher. To accomplish this a shield 13 is Provided, ot

.suitable shape to Vinclose the inner endyof the bearing. This shield may have any desired shape. but commonly it would be shapedl to conform with the end of the bearing. The shield may be made in one, two or more pieces as bestA suits the machine to which it is applied. ln the present case it is made in two parts. an upper and a lower, so that when the cover ot the bearing is tallcen oft, the upper halt` of the shield is taken off with it. rlhe parts ot the shield are fastened in place by screws or other suitable means, and between the inner surface of the shield and the inner surface of the bearing are one or more air spaces 14, the entrance ot which tends and the clearance between theshaft and the wall of the opening is made as small as possible so as to restrict any tendency for oil and air to be sucked out of the bearing due to the action of the armature. rl`his tendency is further decreased by extending the shield into close proximity with the col` lar 15 mounted on the armature shaft.

It is to be understood that my invention is not necessarily limited to dynamo electric machines since it will be useful where ver the conditions are similar to those described, for example it is especially useful 'in connection with bearings on centrifugal fans.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; butl I desire to have it understood that the apparatus shown is only illustrative, and that the invention can be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In combination, a shaft, a bearing supporting said shaft, Aa revolving element mounted on said shaft, said element by its rotation drawing air into itself over said bearing, and means Vforming a spacefor transforming the velocity head of the air drawn over said bearing and before it is drawn into said element into a static head near the inner end of said bearing to prevent said element from withdrawing lubricant from the bearing. p

2. A revolving element which by its rotation produces an air circulation, a shaft for said element in combination with a bearing supporting the shaft therefor, and a shield for the end of theu bearing, said shield being bent away from said revolving elef ment so as to form a space in which the velocity head of the air is transformed into a static head to prevent said element from withdrawingair and lubricant from said bearing. A

3. In combination, a' shaft, a revolving element which by its rotation produces an air circulation, the suction taking place near the shaft and the discharge at a point remotevtherefrom, a bearing for said shaft in close proximity to the revolving member, and means bent away from said revolving velement for transforming the velocity head 4. Inl combination, a revolving element Y which by its motion produces a circulation of air, the direction 0f flow being outward from the shaft, a supporting shaft, ar bearing having a throttled opening throughy which the shaft extends to restrict the escape of lubricant, and a shield bent away from said revolving element located between one end of the bearing and the revolving element and arranged to maintain a static air pressure between it and said bearingv which is substantially equal to that within the latter, thereby preventing said element from sucking air charged with lubricant out of. the bearing. v f

5. In a-n apparatus of the character described, the combination of relatively rotating elements, a shaft for one of said elements, a bearing supporting the-shaft,'and a divided shield bent away from said elements, supported by the parts of the bearing and located between it and therevolving element,

. said shield forming spaces in which the velocity head of the air drawn over said bearing is transformed into a static head to prevent air charged with lubricant from being withdrawn and discharged in-to and through one of said elements.

6. In combination, a revolving element which by its rotation produces an air circulation, a shaft, a bearing therefor in proximity to the revolving element and past which air is drawn, and means bent away from said revolving element for transforming the velocity head of said air draft into static pressure to prevent lubricant from being withdrawn from'the 'bearing by said element.

7. -In combination, a revolving element which by its rota-tion draws air into itself, a shaft, a bearing therefor in proximity to the revolving element and past which air is drawn, and means bent away from said revolving element for transforming the velocity head of said air draft before it is drawn into said element into stat-ic pressure to prevent lubricant from being withdrawn from the bearing by said element.

In witness whereof, I have hereunto set my hand this thirtieth day of October, 1906.

- BRACE H.HAMILToN. Witnesses IonN A. MoMANUs, Jr., HENRY O. VESTENDARP. 

